POS0920 THE EFFECT OF COVID-19 PANDEMIC ON IDIOPATHIC INFLAMMATORY MYOSITIS PATIENTS – A SINGLE CENTRE’S EXPERIENCES
Authors: T. G. Béldi, A. Vincze, B. Miltényi-Szabó, Z. Varga, M. Nagy-Vincze, Z. Griger
Journal: Annals of the Rheumatic Diseases (2022)

Background Pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov2/COVID19) determines the life of clinicians and patients since 2 years. Limited information is available on the nature, prognosis, and complications of SARS-Cov2 virus infection in patients with idiopathic inflammatory myopathies (IIM). There are also few data on triggered humoral response, side effects and disease course after COVID19 infection or vaccination in IIM. Objectives The primary goals of the current research were to assess frequency and outcome of COVID-19 disease and to determine the vaccination rate and effect in our IIM cohort. Secondary objectives were to search for risk factors of infection, predictive factors of hospitalization and to assess incidence of vaccination adverse events, complications and post vaccination breakthrough infections. Methods We retrospectively identified the confirmed COVID19 positive patients and assessed the symptoms, disease course and outcome on 01/06/2021 then patients were prospectively followed. Incidence and complications of vaccination were determined by questionnaires. Anti-SARS-CoV-2 S enzyme electrochemiluminescent immunoassay has been used to assess seroconversion, which measures total antibody (IgM and IgG) to the SARS-CoV2 S protein and SARS-CoV2 N protein. Disease activity was determined by physician global activity. Results A total of 176 patients were screened and 101 participated in the study. By 01/06/2021, the COVID infection rate was 34,7% (mean age: 49.54 years, 72.72% women), which was significantly higher than the national prevalence at that time (8.2%). A third of these infections occurred asymptomatically or mild but 20% of the infected patients were hospitalized, one patient died. Longer disease duration (8.67 vs. 17.87 years; p=0.003) and higher incidence of anti-Jo-1 antibody (57% vs. 10% p=0.018) were significantly associated with hospitalization. All of COVID infected patients became seropositive regardless of immunosuppressive therapy or symptoms severity. 53,4 % of the patients received anti-COVID19 vaccine, 75,9 % choose the mRNA type. The titer of antibodies against the spike protein induced by vaccines showed high variance, but 72,3% of patients became seropositive after vaccination. Higher antibody titer against spike protein was detected after Pfizer-BioNTech vaccination compared to others (177,1 U / ml vs. 81.1 U / ml; p &lt;001). Patients receiving steroid therapy had decreased post-vaccination antibody response compared to those without steroid treatment (94,03 U/ml vs. 165.6 U/ml; p = 0.008). With the follow-up of vaccinated patients, we did not found short term vaccine related major adverse events, but long term data revealed 7,4 % post vaccination disease relapse. Breakthrough infection was detected in 9.25 % of the vaccinated patients, one cancer associated patient without post vaccination seroconversion died due to COVID pneumonia. All the fatal COVID infections occurred in patients with seronegativity to anti- SARS-CoV2 S protein. Conclusion Based on our results, myositis may be associated with an increased risk of infection with SARS-CoV-2. Independent risk factor for hospitalization is anti-Jo1 positivity and longer disease duration. Anti-SARS-CoV2 vaccines are safe, tolerable and strongly recommended for IIM population, but further investigation is required to assess clinical significance of post-vaccination disease flare. Disclosure of Interests None declared